Usually shrinkflation is more subtle, eg the same size bottle has a spacer on the bottom so it's the same size as the 1l bottle but only holds 900ml. No way to buy 1l at that point, and most people don't memorize the unit prices
This. I witnessed it today. I was running out of washing powder, still keeping the old box (6.5 kg, promotional price 25.95 chf sticker). Went to COOP (CH retailer), again "promotion" of Ariel, same price, but the box is now 4.8 kg.
I don't think that's how liquids are legally able to be marketed, at least in any country I'm aware of. A volume measurement on a bottle/can/etc of liquid — whether a drink, a medicine, windshield-wiper fluid, etc — should always be the volume of liquid you get by pouring the container's contents out into a measuring vessel. No real possibility of / benefit to using slack-fill. If they change the shape of a liquid container, it's for logistics reasons (better packing, less likely to puncture/explode, etc.)
Manufacturers can label it as 900 milliliters so they're not lying, but the bottle looks like it's a liter bottle so the customer doesn't really check the listed amount. They should check though, is my point.
I wish changes like this would also trigger a change in the barcode, that fundamentally by law a new unit size of the same product would be given a new number and that number would be on the receipt. If the number was tokenized like a VIN with sub strings representing volume that could be another way to catch this where the information is tied to data text rather than the physical product whose visuals can deceive when in a rushed shopping event.
Probably not but it would enable that sort of analysis should anyone find a way to easily automate that process someday. It’s one mechanism for feedback that probably not everyone has to do but a few could and their efforts would benefit the wider consumer base I’d imagine. If someone posted that raw data and analysis publicly that would be a website I’d visit from time to time.
